1. Field of the Invention
The present invention relates to a communication apparatus having a power-saving function.
2. Description of the Related Art
Energy Efficient Ethernet (EEE) exists as a power-saving function of Ethernet, which is a wired network complying with Institute of Electrical and Electronics Engineers (IEEE) 802.3. The EEE employs a Low Power Idle (LPI) technique for reducing power consumption (standby power requirement) in a time period (standby state) in which data communication is not performed in a wired interface (corresponding to a physical layer (PHY)) (Japanese Patent Application Laid-Open No. 2011-212946).
To use the EEE, it is confirmed that a communication apparatus (for example, a printer) and another communication apparatus (for example, a hub) as a communication partner support the EEE in auto negotiation performed when the communication apparatus and the other communication apparatus establish a communication link. Herein, when even one of the communication apparatus and the other communication apparatus does not support the EEE (also including a case where the EEE is disabled), the EEE cannot be used.
When a setting for the EEE is changed in the communication apparatus (more specifically, when the EEE is switched from an enabled state to a disabled state, or the EEE is switched from the disabled state to the enabled state), it is necessary to reperform the auto negotiation. Since the auto negotiation is performed when the communication link is established, the communication apparatus disconnects the communication link, and then reestablishes the communication link to perform the auto negotiation.
If the communication apparatus switches between the enabled state and the disabled state of the power-saving function (for example, the EEE) in the wired interface when the communication apparatus receives data, the communication link between the communication apparatus and the other communication apparatus is disconnected. That may bring about a failure in the reception of the data to cause loss of ability to perform predetermined processing.